[PATCH v3 26/35] x86/bugs: Add attack vector controls for srbds

David Kaplan
2025-01-08T20:25:56Z

Use attack vector controls to determine if srbds mitigation is required.

Signed-off-by: David Kaplan <david.kaplan@amd.com>
---
arch/x86/kernel/cpu/bugs.c | 10 ++++++++--
1 file changed, 8 insertions(+), 2 deletions(-)

diff --git a/arch/x86/kernel/cpu/bugs.c b/arch/x86/kernel/cpu/bugs.c
index d9b12c706fc0..c6b395608c3f 100644
--- a/arch/x86/kernel/cpu/bugs.c
+++ b/arch/x86/kernel/cpu/bugs.c
@@ -897,8 +897,14 @@ static void __init srbds_select_mitigation(void)
if (!boot_cpu_has_bug(X86_BUG_SRBDS))
return;

- if (srbds_mitigation == SRBDS_MITIGATION_AUTO)
- srbds_mitigation = SRBDS_MITIGATION_FULL;
+ if (srbds_mitigation == SRBDS_MITIGATION_AUTO) {
+ if (should_mitigate_vuln(X86_BUG_SRBDS))
+ srbds_mitigation = SRBDS_MITIGATION_FULL;
+ else {
+ srbds_mitigation = SRBDS_MITIGATION_OFF;
+ return;
+ }
+ }

/*
* Check to see if this is one of the MDS_NO systems supporting TSX that
--
2.34.1